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Unique biodiversity hotspot faces destruction

The tropical rainforests of Papua New Guinea – in the top ten of the world’s most biodiverse hotspots – are disappearing faster than anyone realised, according to a new report.

The report, by a team led by Phil Shearman of the Remote Sensing Centre at the University of Papua New Guinea in Port Moresby, was presented this Monday at a workshop on climate change, forests and carbon trading in Port Moresby. It finds that the PNG forests are being cleared at least as fast as those in the Amazon and Southeast Asia.

The Shearman team used pattern recognition software called eCognition to analysis satellite images from 2002 to 2007, and then compared them with vegetation maps from the 1970s, produced by the Australian Defence Forces. They also factored in population growth, logging rates and evidence of fire damage.

Thinning rapidly

Their study found that PNG’s forests were being cleared or degraded at a rate of 1.4% per year in 2002, increasing to 1.7% per year in 2007. If clearing and degradation continues unchecked, over half of the forest that existed when PNG became independent from Australia in 1975 will have been destroyed by 2021, according to the report. The Brazilian Amazon is losing forest at the rate of 0.9% per year.

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“PNG is still one of the most forested nations on the planet, but forest is being lost at a far higher rate than any one thought,” says Shearman. “The rainforests are on the same trajectory – but from several decades back – as other Southeast Asian forest.”

PNG makes up just under half the pacific island of New Guinea, which totals 786,000 square kilometres, roughly the size of France. New Guinea, which forms the Northern edge of the Australian tectonic plate, is a unique biogeographical area. It is home to six to eight per cent of the world’s biodiversity on only 0.5% of its land, and much of that diversity is concentrated in the rainforests of PNG.

Until the new findings, anecdotal evidence combined with out-of-date official information about the PNG forests had led many experts to believe that the forests had been left largely undamaged by human activity, says biologist Allen Allison at the Bishop Museum in Honolulu, who is an expert on New Guinea. The Food and Agricultural Organisation lists the rate of forest loss in PNG as 0.5% per year.

Blame the loggers

According to the new report, 46% of the area of forest that has been destroyed has been used by subsistence farmers – the population of PNG is growing at 3% per year. But the authors blamed loggers for most of the loss.

“Malaysia is virtually completely logged out. Indonesia is nearly logged out. So in the last 15 years the logging companies have moved to PNG,” says tropical ecologist Julian Ash of the Australian National University in Canberra, and one of the report’s authors. Ninety-eight per cent of the timber goes to China, according PNG’s minister for forests, Beiden Namah.